1.Field of the Invention
The invention relates to a device for the leak-tight sealing of openings in containers and for the purification treatment of ambient air located therein as a result of opening and closing cycles, these containers being intended for packaging of products that are sensitive to gaseous pollutants present in this ambient air.
2.Description of Related Art
The invention is related particularly to a device for leak-tight sealing of the access opening in containers and for purification treatment of ambient air located in these containers as a result of opening and closing cycles, these containers being intended for packaging of products sensitive to gaseous pollutants. This leak-tight sealing and purification treatment device is composed of the following, according to a new combination of known or unknown means:                a leak-tight sealing means in the container access opening,        a means of assembly of the sealing device on the container access opening,        a means of connection between the sealing means and the assembly means of the device,        at least one means of checking tamper resistance        a mechanical assistance means controlling the amplitude of the opening angle and assisting with opening and closing of the said sealing means.        
The leak-tight sealing and purification treatment device is a single part made of thermoplastic materials using plastics technologies.
In the following and throughout the description of the object according to the invention:                The gaseous pollutants that may be present in the ambient air in the leak-tight packaging containers for sensitive products may for example be water vapour, oxygen (O2), ammonia (NH3), alcohols, aldehydes, ketones, sulphur dioxide (SO2), hydrogen sulphide (H2S), mercaptans, alkenes particularly including ethylene, alkynes, carbon dioxide (CO2), carbon monoxide (CO), nitrogen dioxide (NO2), alkanes and particularly methane (CH4), halogens and particularly fluorine, bacteria in suspension in the ambient air and others.        Products sensitive to gaseous pollutants present in the ambient air may be defined as being:                    materials in the solid state, in a wide variety of forms such as powdery, granules, pellets, particularly for effervescent, sugar-coated or agglomerated products, and/or            objects that may be in various shapes and particularly oblong shapes.                        
Thus, and according to this definition:                Materials sensitive to pollutants like those mentioned above to be packaged in a leak-tight container are usually medicaments, particularly effervescent medicaments, that should be protected so that their reactive effectiveness does not change in time due to reaction with at least one of the pollutants, and/or so that their physical integrity is maintained in the long term, and for example to avoid a change to their mechanical cohesion.        Objects sensitive to pollutants, to be packaged in a leak-tight container are particularly oblong in shape, and they may have an approximately polygonal, circular, elliptical or elongated cross-section and are consumables. Such objects include particularly small tongues, reactive bands or rigid lamellae used for example for diagnosis or checking purposes in the medical field, dressings, food products such as chewing-gum, tooth picks, small sticks or others.        
For obvious reasons, particularly hygiene reasons but also to prevent any degradation and thus improve the conservation life of products sensitive to pollutants present in ambient air, these products are placed in containers protected from physicochemical attacks caused by the concentration of gaseous pollutants, but also protected from light, particularly UV rays, or from degradation due to mechanical causes such as shocks.
Establishment of the state of the art demonstrates the existence of stoppers for closing containers, the essential function of which is that they have drying properties: these particular containers are designed to receive and contain products sensitive to ambient humidity, that must be protected by creating the driest possible internal ambient atmosphere to prevent a regain of humidity, since such regain of humidity by absorption could in particular react with the said products and reduce their reactivity causing mechanical weakness under shock, spalling or disintegration in the container.
Many products are particularly sensitive to ambient humidity, and for example and more precisely may include medicament test materials in powdery form or in more sophisticated forms such as granules, tablets, pellets, oblong shaped objects such as bands for tests or other purposes, more specifically including products that are particularly sensitive to humidity.
These drying and leak-tight containers according to the state of the art for the storage of products sensitive to ambient humidity are tubular shaped or may be in any other shape and, provided with an opening, are closed off by a stopper that may or may not be fixed to the tubular part through a solidarisation means such as a narrow flexible strip made from a polymer material identical to the material from which the container and the stopper are made.
These drying and leak-tight containers are provided with internal drying means that are either a coating or insert made using a drying thermoplastic polymer composition placed inside the containers on the inner surface of the bottom of the tube and/or on the inner surface of the sidewall of the tube, or a drying granular material placed in a particular housing on the inner surface of the stopper.
All these drying means are put into place separately or simultaneously to increase their dehydrating efficiency due to a mass effect.
These closed containers are formed from:                a tubular casing provided with a bottom at one of its ends, the other end being left open so that the said casing can be filled,        and a closing means that may be a removable stopper that fits into the open end of the tubular casing, or a stopper-cap that also fits into the open end but is connected to the tubular casing by a flexible link such as a narrow flexible polymer strip acting as a hinge.        
All these containers and their removable or connected closing means are made from thermoplastic polymer compositions according to techniques well known in plastics techniques.
Means of sealing containers and the drying containers closed by these means for packaging materials and/or objects sensitive to ambient humidity, are described in the state of the art and are distinguished from each other essentially by their architecture, particularly by drying means used in the said containers and by the architecture of the container closing means.
According to a first type of drying container sealing means used in the state of the art, this first closing means is a male type stopper-cap connected to the tubular part of the casing of the drying container through a mechanical means composed of a force fitting ring surrounding the said tubular casing and a flexible and narrow connecting strip between the stopper-cap and the ring, the drying container being formed from a tubular casing open at one of its ends to provide access to the receptacle area.
A document (U.S. Pat. No. 4,934,556) describes such a sealing means and a drying container closed by this means, the closed assembly forming the container being composed of:                a sealing means comprising a male type stopper-cap, a ring for a force fitting of the said stopper-cap on the tubular casing of the container, a tamper resistance telltale to be torn off, connecting the assembly ring to the outer periphery of the stopper-cap and a flexible strip acting as a narrow connecting hinge between the stopper-cap and the said ring, the sealing means being made from a thermoplastic polymer material that may be different from the material used to make the tubular casing;        a tubular casing made of a thermoplastic polymer material, provided with a bottom at one of its ends and open at other end, acting as a receptacle for the materials to be packaged, on which the sealing means is installed through the ring.        
The male type stopper-cap is formed from a bottom and a descending peripheral skirt called the outer skirt that delimit a cylindrical cavity inside which there is a housing containing a powdery drying agent in direct contact with the internal gaseous medium to be dehydrated.
The sealing means comprising the stopper-cap, the force fitting assembly ring, the tamper resistance telltale, and a single, flexible, narrow connecting strip connecting the stopper-cap to the ring forms an assembly made of a thermoplastic polymer material independent from the tubular casing forming the receptacle of the drying container.
This type of drying stopper-cap designed to close a tubular casing used for packaging of products sensitive to humidity raises uncertainties about its capability to guarantee fast and complete desiccation of the said products when opening/closing the said packaging container. This fact appears to be:                the result of insufficient leak-tightness between the male type stopper-cap and the tubular casing, since the architecture of the said stopper-cap does not appear to be suitable for making the container leak-tight when external-internal exchanges of gaseous volumes containing humidity that should be quickly dehydrated;        also, at least partly, the consequence of the flexible connecting means between the cover-cap and the force fitting ring surrounding the casing, since it is impossible to achieve correct positioning of this means consisting of a narrow flexible strip made of a polymer material acting as a hinge when closing the casing, due to lack of any guidance prior to the said closing.        
This type of stopper-cap also requires a manipulation of the closed container with two hands, both to open it and to close it.
Another type of drying container sealing means known in the state of the art is a female type stopper-cap fixed to the drying container casing through a means consisting of a narrow flexible connecting strip, the tubular casing, the stopper-cap and the connecting means being made by injection with the same thermoplastic polymer material.
A document (EP 1 352 844) describes such a type of drying container closing means, the closed assembly forming the container being composed of:                a tubular casing made of a thermoplastic polymer material provided with a bottom at one of its ends and open at the other end;        a female type stopper-cap without a descending inner skirt that covers the wall of the open end of the container casing when in the closed position, leak-tightness being capable of being assured by the contact between the inner surface of the bottom of the cap of the stopper-cap and the periphery of the open end of the tubular casing, the said stopper-cap being provided with a perforated cavity on its inner surface into which a drying agent in pellet form can be added and connected to the casing through a link consisting of a narrow flexible polymer strip, the casing, the cap and the connection between the cap and the casing being made in a single part during a single plastics forming operation, for example by injection moulding;        a drying insert consisting of a thermoplastic polymer material containing drying materials, this insert possibly covering the bottom and the inner wall of the said casing simultaneously;        the stopper-cap without a descending inner peripheral skirt cannot create a surface-to-surface type leak-tightness with the inner surface of the open end of the tubular casing, leak-tightness is apparently only obtained through contact between the inner surface of the bottom of the stopper-cap and the periphery of the open end of the casing;        the stopper-cap is not particularly suitable for creating leak-tightness between the inside and the outside of the container due to its architecture, but also due to its flexible connecting means with the casing, since this means cannot be used to position the cap when it is closed due to this very high flexibility and consequently the lack of sufficient longitudinal and lateral mechanical stiffness necessary for guidance of the stopper-cap at the time that it is closed;        it requires the use of two hands to manipulate the closed container for opening and closing.        
Another document (GB 2 224 309) describes a hinged sealing device, in other words a stopper for a thermoplastic container and more particularly for containers comprising a very narrow, coaxial distribution opening and intended for distribution of liquid. The stopper comprises a tubular peripheral wall on the inner surface of its upper end with a section adapted to the section of the narrow distribution opening to be sealed, and making the stopper leak-tight when the stopper is in the closed position.
The said device is composed of two parts, the first part being a click fitting cap pivoting on two hinges composed of two flexible strips defining a first rotation axis, the second part being a base to be fixed on the opening of a container to be sealed, and a flexible and elastic link making the connection between these two members and being such that the stopper can occupy two rest positions, one closed and the other open, on each side of an intermediate position occupied during the movement.
The said flexible link with a return function is “S” shaped and is connected semi-rigidly and elastically firstly to the stopper at a precise point, and secondly to the outer surface of the base at another precise point. The connection between the ends of the flexible link firstly to the stopper and secondly to the outer surface of the base is characterised by the lack of hinges due to the continuity of the thickness of the wall.
However, this device has several disadvantages that can be the result of a form of embrittlement of the material forming the flexible link. The “S” shape of the flexible link when the device changes from a closed position to an open position contributes to creating two opposing forces about an inflection point located approximately at the middle of the flexible link, this inflection point delimiting a convex area of the strip on the downstream side and an area of the strip on the upstream side that remains concave.
Thus, the slope inversion due to the “S” deformation at the time of closure causes an acceleration of the movement acting on the convex part of the strip, in other words between the cap and the inflection point, to restore the initial stable concave state of the entire strip.
Therefore this type of flexible link performing the return function is deformed by the slope inversion over its entire length, this total and constant mechanical mobilisation of the material from which the flexible link is made tending to weaken it.
Thus, apparently none of the drying stoppers-caps according to the state of the art is adequate for packaging products sensitive to relative humidity and/or other gaseous pollutants in appropriate containers under optimum conditions, and to enable these containers to develop remarkable characteristics such as:                quickly absorbing humidity and/or gaseous pollutants, particularly the pollutants mentioned above in a container even after a fast opening/closing cycle,        easy manipulation of the said stoppers-caps with a single hand and keeping the container sealed, and        providing mechanical assistance with opening/closing the stopper-cap.        
Many objectives are assigned to the leak-tight sealing device according to the invention for packaging containers and for purification treatment of the ambient air located in the container by elimination of the gaseous pollutants present, such that it minimises the above mentioned disadvantages and provides appropriate solutions better than the solutions provided with the various means used in sealing devices described in the state of the art.
Some of the most important objectives of the sealing device according to the invention for packaging containers for products sensitive to gaseous pollutants are means that in combination assure:                easy opening/closing of the leak-tight sealing and treatment device by precise mechanical guidance of the sealing means so that sealing takes place precisely with no manual guidance, with excellent positioning,        mechanically assisted opening/closing of the leak-tight sealing and treatment device to accelerate opening and closing of the sealing means and to limit the amplitude of the opening angle at the end of travel so as to put the sealing means in a suitable position for closing with the use of a single finger of the hand holding the container,        complete leak-tightness set up between the opening to be closed and the sealing means,        at least one tamper resistance means of the container before first opening,        dynamic treatment of gaseous pollutants, and particularly the water vapour present in the container, better than what is observed in the state of the art, in other words with a greater capacity to eliminate internal pollution created when the container is opened and closed, to prevent packaged products sensitive to gaseous pollutants from adsorbing and/or reacting partly with the said pollutants and an ability to keep the content of gaseous pollutants internal to the container at a low and relatively constant level, except during opening/closing cycles, to provide the best possible protection to the packaged products sensitive to these pollutants.        